Process of producing compound metal bodies.



0. H. DE LAPOATTERIE. PROCESS 0F PRODUCING COMPOUND METAL BODIES.

APPLICATION FILED APR. l. 1914.

Patented Apr. 18, 1916.

2 SHEETS-SHEET I- 0. H. DE LAPOTTERIE. PaocEss oF Ponucmc coMPouNn METAL BODIES. APPLICATION FILED APR. 7, l9l4.

Patented 18, 1916.

2 SH HEET 2- @TTU H. DE LAPOTTlERIlE, OlF KOPPIEL, PENNSYLVANIA.'

BOCESS 01E PROIDUGING COOUND METL BODIES.

Specification of Letters Patent. i

Patented am. i, raie.

Application led April 7, 191e. Serial No. 830,198.

To all who/m, t may concern Be it known that l, O'r'ro H. DE Lar'o'i`- TERIE, a citizen of the United States, residing at Koppel, in the county of Beaver and State of Pennsylvania, have invented certain new and useful Improvements in Brocesses of Producing Compound Metal Bodies, of which the following is a specification.

Pl`his invention relates to processes of producing compound metal bodies and consists in a method of uniting layers or strata of unlike metals, i. e, metals or alloys of unlike chemical nature, whereby such metals and'alloys are so firmly and permanently united' that theyl will resist the action of cleaving tools, violent temperature changes, and distortion, to separate them.. Because the nature of a union between metals which are unlike in the above sense, produced according to the method herein described, would be considered by those skilled in the art as an alloyed one, and also because ll lack a more suitable term, l shall refer to a union so. secured as an alloyed one, alloy united, or plain alloy union, without intending thereby to limit or confine myselfto any particular theory as to the actual nature of the union between the unlike metals, merely using the said terms as distinguishing and convenient ones.

By the method hereinafter described it is possible to produce compound metal ingots, and also manufactured articles, of compound metal, such as plates, sheets, rods, tube, wire, andthe like, and the same may 4 be either the product of the compound metal ingot extended by drawing, rolling, pressing, hammering, etc., or made by coating finished metal articles, without departing from the spirit of my invention.

lt. is well known that it is very dicult to unite, permanently, unlike metals, such as wrought iroriand the'various steels, with metals of unlike nature such as copper,l silver, gold, y aluminum, cupriferous alloys v(such as'bronze, brass, etc.), aluminum alloys (such as aluminum bronze, manganese bronze, ete).

llt is also generally considered that metals of high melting-point cannot be cast at their ordinary casting temperatures against a metal surface coated with a metal of low melting temperature such as tin, without causing detrimental oxidation, volatilization, or vaporization of the metal of lov7 melting temperature,-due to the fact,n that the temperature necessary to bring the metals of high melting temperature to a casting condition is sufficient to oxidize, volatilize, or vaporize the metal of low melting temperature, and prevent a perfect union being formed.

It has further heretofore been found necessary in the art of coating metals with metals of high melting point to protect a film coating secured from such metals yor alloys from contact with theair, by neutral gases,

Y vaporized atmospheres, chemical substances 'of `a solvent or protecting nature, etc., be-

cause the temperatures heretofore necessary to secure such film coatings were suiiiciently high tovcause oxidation or other detrimental action.

It is one of the objects of my invention to eliminate these necessities.

The fundamental discovery upon which my new process rests isthat while unlike metals and alloys of high melting temperatures, such as above named, do not unite readily under the usual conditions of melting, and volatilize metals of low melting temperature if cast thereagainst at the ordinary casting temperature of such high melting metals; yet, if certain deoxidized and deoxidizing alloys of such high meltin metals as above referredto are maintamed at a temperature considerably below that at whichthey are usually cast, and the metals to loe-coated are previously coated with a metal oralloy of low -melting temperature, detrimental oxidation, volatilization, and vaporization are avoided, and the use of protectin apparatuses and added protecting manu actured influences for the film coatings .obtained are eliminated. Illhe union secured is absolutely permanent,pbe ing inseparable by change of temperature such as heating to red heat and plunging into ice water; by cleaving tools, such as a cold chisel or like tool applied along the line of 55 Y sarily be of the deoxidizedmetal used as alinking nexus for other metals, solong as.

l demarcation (the tool tending to dig into:

Deoaidized and deoxidizing alloys., by

which I mean such alloys -as alumlnumbronze, at a temperature, which may be called the semi-molten temperature, display" extraordinary chemical or physical acA dissimilar 2 metals.

' tivity of semi-molten deoxidized and deoxi-l dizing alloys and theconcomitant heighten# ..tivity, readily uniting with metals dissimilar thereto as iron and steel, if the ,latter are previously coated-*With a metal 0r alloy of low melting temperature, such as tin. Nor do they cause, or are they themselves, when in this semi-molten4 condition, subject to the detrimental infiuences which prevent a unionl between the dissimilar metalsy at the ordi' nary casting'temperatures of'such alloys or While the fact is as stated I am unable to give an explanation of the phenomenon. Possibly it is due to a catalytic condition existing at this temperaf ture, or to some eutectic 'molecular change accompanied by changes in physical properties. This peculiar. increase of chemical ac j ing of their affinity for certain other metals,

whether these characteristics be molecular, atomic, catalytic, eutectic, `or physico-chemical, if heretofore observed has not to my knowledge been' applied to the uniting of unlikelmetals Aof the classes vherein contemplated, and/I [am not aware that any at tempt has ever been made to produce between contacting surfaces of metals to be joineda coating of deoxidizing vmetal at a `temperature so low that detrimental oxidation ,of the film 4coating secured has i been avoided andthe use 0f added manufaclike steel, with copper,

turedy deoxidizing'influences therefore eliminated.

As an illustration of a deoxidized anddeoxidizing, metal or alloyt0 be used as a coatingand uniting film, a ten per cent. aluminum bronzel may be taken. This alloy has va casting temperature'of about 1800 F. As practised inthis ivnventionpthe .semimolten condition exists at a temperature considerably below 1800 F.

In coating metal process, the entire coating need not neces the main coating desired has affinity for and will 'combine readily withfthe film coating. For example,

`I first film-coat the steel with tin, next with a-deoxidized alloy such as aluminum bronze at semi-molten temperature, and then cast against "or conwith molten metal by whencoatings; a ferrous metal a metal Such as copper at a convenient cast-- ing temperature of the copper. The molten copper, being of metal like unto the film coating, and of higher temperature, combines readily with the deoxidizped and deoXidizing film coating, due to the powerful affinity, purifying, and reducing action created along the surface of union by the deoxidized metal previously applied. "The scavenging and deoxidizing influences, Which, in the first instance, caused the removal of impurities, dissolved oxids, and o ccluded gases from the film coating, now prevent the added molten copper taking them up again along the line of union between the copper and steel, securing a positive union, free from fiaws, pores, impurifl ties or other defects. Nor will re-heating of the joined bodies of unlike metals in further working deteriorate in any manner the union along the surface of Contact between the joined metals. In fact, I have found that the metal along the plane of joinder is actually improved thereby. 4vWhen the process is properly carried out the alloying of the film coating along the line of joinder of the copper and steel is confined to an excessively thin film between approximate sur,

faces, the main portlon of the metals pos-k sessing their ordinary properties.

It is not essential in securing the film coating that the article to be coated shall be confined for a longperiod of time in the bath of semi-molten deoxidized metal, and I have found that the thickness of coating secured (to a certain degree) is in direct proportion to the length of time that the articles are immersed in the. semi-molten metal. In practice when I desire to use a film coating as a linking nexus between other metals, I usually use a coating of the thickness Isecured by slowly lowering and raising the article t0 be coated in and out of a bath of the semi-molten metal, anddo not leave it .stationary in the bath any great length of time. Yet if a clean piece of tin-coated steel,

previouslylieated to a temperature below the volatilizing or oxidizing temperature of the tin on such steel,'is passed rapidly 1n and out v or through a bath of semi-molten deoxidized metal such as aluminum bronze, it will be found to becoated with a firm thin permanent cohering film of thedeoxidized alloy, so thin, bright, smooth, and free from fiaws, pores, etc., as to be scarcely perceptible 'to the eye. The coating so secured, if subjected to a strong oxidizing infiuence for along period of time will be-found to develop the rich colorof the deoxidized alloy used. In many cases this exceptionally thin film coating is sufficient 'to secure a union between 'otherl unlike metals, but find that the chemical activitiesand affinities of the lm Atti armate coating is more pronounced for other metals if a film coating a little richer in deoxidized alloy is secured. A film coating secured in the manner above described does not lose its brightness byratmospheric contamination as is common in the art of working metals of high melting temperature and it can be v handled with perfect freedom in an oxidizing atmosphere such as air without fearof contamination of the film-coating in any manner. This has never been possible heretofore in the art of working metals of the class herein contemplated.

By my process, lf am enabled for the first time in the history of the art, l believe, to secure a union between unlike metals of high melting temperature at a temperature so low that oxidation or contamination of the filmcoating secured is avoided, and the use of added manufactured protecting apparatuses and influences necessary in other processes (such as casings of neutral gases, vaporized atmospheres, chemical fluxes, and other solvents of occluded gases and impurities) are eliminated. This is an important feature in my invention, as it permits perfect freedom of inspection of the film-coating, and assures a high percentage of perfect finished products. lt also permits rehandling' of the coated articles at various stages of the process and counteracts negligence on the part of the workmen employed.

lin practice, to determine when the semimolten or operating condition has been reached, thin pieces of tin-coated steel wire may be kept handy and dipped into the metal from time to time and the coating secured examined in the open air. lt is also easy by the latter method of testing to determine when the limit of the semi-molten or operating temperature is exceeded, as the testing wire will then leave the bath uncoated and blackenedk to an excessive degree, and in this case, all that is necessary is to reduct the heating and permit themolten metal to return to asemimoltencondition. lhave found however that aluminum zronze has a considerable range of plasticity .between its plastic and liquid conditionand with a fairamount of attention on the part of the operator little trouble is experienced.

ln the accompanying drawings,-Figure 1 shows a cylindrical ingot in elevation, and an attached screw-eye for handling; Fig. 2 is aremovable center to be inserted in the bottom of the ingot; Fig. 3 is an end View of the ingot in Fig. l; Fig. 4c shows'the ingot centered in a mold: Figs. 5 and 6 are top and side views of a top centering spider; Figs. 7 and 8 are longitudinal and transverse views of a sectional mold showing an octagonal-shaped'ingotfFigs 9 and 10 are views of its top centering spider; Fig. 11 is a transverse View of a sectional mold for coating square ingots; Fig. 12 is a similar view for coating rectangular ingots; Fig. 13 shows a two-compartment furnace in which the ingots receive preliminary metallic coatings; Fi 14Cv shows a film-coated ingot; Fig. 15 s ows a piece of coated steel separated close to the union; and Fig. 16 shows a section of a compound ingot.

lin illustrating my process, ll will use as an example the uniting of copper and steel, and will assume that steel ingots are to be coated on all sides with a substantial coating l of copper and then extended by manufacture into sheets, rods, and other Varieties by the usual methods of metal working such as rolling, hammering, pressing, drawing, etc. For convenience in handling the ingots have attached to them the rings 2 and bottom centers 3. A suitable number of steel ingots are first thoroughly cleaned by sand blasting or other mechanical means, and are then pickled in hydrochloric or other nonoxygenating acid in any practical manner. After pickling they are immersed in a solution of commercial sal-ammoniac z'. e. one pound of sal-ammoniac to about one quart of water which is kept warm by a suitable heating source, such as a jet of steam. The ingots when warm are taken from the bath and put into a hot drying chamber maintained at about 300o F. and left until the moisture has been evaporated from their surfaces. The ingot with its surface heated to about 300 F. from the heat absorbed from the bath and drying-room is now taken to a second bath 4c which contains a low-melting metal or alloy, such as molten tin, at a temperature of fluidity commonly 'practised in tinning (see Fig. 13). quantity yof commercial sal-ammoniac 'is' thrown upon the surface of the molten tin as the ingot is slowly lowered into the bath. After ashort period of time depending upon the size of the ingot, the heat of theY tin, and the heat absorbed in the previous operations, the ingot is raised a few inches out ofthe bath to see if the tin which has a strong aflinity for steel under the conditions named, is cohering thereto in a very thin film and when this is observed to be the result, the ingot is drawn out of the bath through mechanical wipers in order to re- `move excess metal. It is next carefully inmyself to the specific proportions herein. This bath of aluminum bronze. is maintained, in the furnace 6 heated preferably by a gas or oil-burner 6, in a semi-molten condition. The exact limits of temperature of this semi-molten conditionl have not been determined, but by use of the test pieces, as above referred to, the operator will readily ascertain when the proper condition has been reached. vI prefer to use this bath when it is in a state of medium plasticity, which is obtained by first melting thealloy and then permitting it to cool to the requisite degree. Vhen the test pieces show that the semi-molten condition has been reached, the heat is again applied and regulated to maintain the bath in this condition. I have worked with this bath up to a`point where bath 5 of semi-molten deoxidized alloy without leaving it stationary therein any longer than necessary. On withdrawing the now alloy-coated ingot 7 it will have been coated with a thin, firm, permanent, cohering film coating 8, shown greatly exaggerated, of the metals used, see Fig. 14, and this coating will be so thin, smooth, bright, and free from fiaws as to be barely perceptible at first glance. No protection from the action of the air need be provided as the film-coating has been secured at a temperature so low that it is not oxidized and is not subject to the detrimental influences which make protection necessary in` other processes. The bright alloy-coated ingot, with its surface now more highly heated from contact with the semi-molten bath of deoxidized alloy, is again inspected with perfect freedom, and if` satisfactory is centered in a cover 9 of an ingot mold 10 used in the next operation. It is then taken to this mold (Fig. 4) `which contains molterr copper of eXtreme purity at its ordinary casting temperature and centered therein; or if desired, the copper 16 may be cast into the mold 10, throughports 11, provided in the cover 9 for that purpose, after the ingot has been lcentered in the old'lO.

The mold used is usually coated with a wash made from plumbago and water dried by heating, and the molten copper therein I usually cover with charcoal and pole as is well known inthe art. The deoxidized film-coated ingot 7 is now centered in the .molten copper in the mold by the cover 9 (in which it is centered) fitting true on the mold, and secured by the pressure-clamp 20,

which prevents the ingot fioating in the molten copper. The copper 16 in the mold being of vlike metal unto the film-coating 8 :alarmes on the steel ingot readily combines therewith to form a perfect union, due to the powerful afiinity, purifying and reducing action created along the line of joinder by the deoxidizing metal 5 previously applied to the copper of the film-coating; and the scavenging and deoxidizing influences which in the first instance removed from the copper of the film-coating the impurities, oxids, dissolved oxids, and occluded gases, now have the same effect on the added molten copper 16, along the surface of union .between the copper and steel.

As soon as the molten copper 16 has solidified to the extent that it will permit handling, pressure-clamp 20 is removed, the eyelet 2 is reinstated, and the finished ingot is removed from the mold and subjected to a soaking heat and worked into extended ware by the usual methods of manufacture such as rolling, drawing, pressing, hammering, spinning, etc., or if desired the compound ingot ofcopper and steel may be permitted to cool entirely, and be reheatedxand 'worked at some future time.

rslightly tapering, at 14, may, if desired, be

of uniform bore, since the molds may be unbolted and removed from the ingot, instead of removing the latter from the top. Vith the sectional molds 13, the overlapping joints 15 are first coated with a paste of graphite and oil, enabling an easy separation of the sections, and preventing leakage of molten metal.V

In Fig. 16 I have shown a section of a compound metal body of unlike metals produced according to my invention. The'central portion 1 is steel, the outer portions 16 pure copper, and the film-coating 8 used as a linking nexus between the metals is a deoxidized alloy secured at semi-molten temperature. The film-coating 8 or linking nexus, as shown. is greatly exaggerated for the purpose of illustration.

While I have specified copper and steel as the metals used, the same process is applicablevto coating or combining other metals one with another. No added manufactured protections or non-metallic substances of a protecting, fiuxing, or solvent nature are nectemperature under the conditions named;`

misdaan to the union between the copper 16 and steel 1, was also rolled parallel to the union to flatten it, then heated to red heat three times and plunged into ice water each time, and was then distorted by bending until the metals broke, the break occurring adjacent the line of union between the joined metals and in no manner indicating a rupture along the line of demarcation. This line of demarcation between the joined metals does not give any ordinary visible evidence of the previous presence of the film-coating referred to, the contacting surfaces being combined so thoroughly that the metals joined appear to be pure copper and steel.

In coating metals with other metals of unlike nature the base or core metal 1 need not necessarily be of iron or steel, as I can combine by the method herein described any metals which readily accept a film-coating of a deoxidized metal secured at semi-molten temperature. It is also obvious that all sides of film-coated articles need not be coated with the same metal, for as is well known a protector may be used to protect one or more sides of the film-coated article from a metal applied, the protector removed, or partly removed, and another unlike metal applied to the surface then exposed and in coating metals by the process described, it is readily seen that with a film-coating secured in the manner stated, the metal caused to combine therewith need not be in an entire state of fusion as the contacting surface of they metals to be applied need only be brought to a temperature sufficiently high to cause combining with the deoxidized film-coating secured at semi-molten temperature.

By the terms iron and steel in certain of the claims herein, I designate all forms of iron or steel, which will readily accept a deoxidized film-coating at semi-molten and by the term tin I designate a metal such as tin, of low melting point, that may be used for coating ferrous metals, as described herein. I do not confine myself necessarily to pure metals, as certain modifications thereof can be used with fair results. I have also applied such metal of low melting temperature by precipitation, but as this method does not accomplish the preliminary heating necessary to prevent an undue amount of heat being abstracted from the semi-molten deoxidized metal, I prefer to use a metal of low melting-point in a molten condition.

By the clause added manufactured protecting apparatuses and influences, I mean to designate the protectors generally considered necessary in this art to protect a film coating of metals having a melting-point above 900 F. from detrimental atmospheric affection, also the added applied nonmetallic constituents used to protect film coatings or cause other metals to combine therewith. And by the expression liquid and solid metals in some of the claims the Word liquid refers to the metal at semimolten temperature, while the word solid refers to the base metal to which the metal at semimolten temperature is applied.

Iclaim:

1. rll`he process of producing compound metal bodies of unlike metals, which comprises film-coating a surface of one such metal with a' metal or alloy of low-melting temperature and then contacting it with a deoxidized metal or alloy at a semi-molten temperature, and causing this second metal or alloy to solidify thereon. l

2. The process of producing compound metal bodies of unlike metals, Which comprises film-coating a surface of one such metal with a deoxidized metal by contacting said first metal with such deoxidized metal at a. semi-molten temperature, said filmcoating of deoXidized metal secured to said first metal through the agency of a prior coating of a third metal.

3. The/,process of producing compound metal bodies of unlike metals, which comprises film-coating a surface of one such metal by contacting itI with a deoxidized metal at a semi-molten temperature, said film-coatingof deoxidized metal secured to said first metal through lthe agency of a prior coating of a third metal, and then bringing a substantial body of another metal in contact with the deoXidized film-coated surface so secured and causing it to combine therewith.

4. The process of producing compound metal bodies of unlike metals, which comprises coating the surface of one such metal with a metal or alloy having a meltingpoint below 900O F., and contacting therewith a semi-molten deoxidized metal having a melting-point above 900 F., and thereafter causing a metal having a melting-point above 900o F. to combine therewith.

5. The process of producing compound metal bodies of unlike metals, which comprises film-coating one such metal with a plurality of metal films, including one of high melting temperature, at a temperature so low that detrimental oxidation of the film-coatings secured is avoided.

6. The processv of producing compound metal bodies, which comprises film-coating the surfaces of one such metal with a metal or alloy of low melting-point and then contacting the film-coated surfaces with a semimolten deoXidiZed metal and thereafter causing a substantial body of another metal to combine with the film-coating so formed.

bodies of Viron and non-ferrous metal, which Athen contacting the coated surface with a ,deoXidized metal at a semi-molten temperature and thereafter causing a substantial body of non-ferrous metal to combine therewith.

8. The process of producing compound bodies of iron and non-ferrous metals, which comprises coating the surfaces of one of such group with tin, then contacting the coated surfaces with aluminum bronze at a semi-molten temperature and thereafter causing a substantial bodyof metal having aflinity for thecoating, to combine therewith.

9. The' process of producing compound bodies of unlike metals, which comprises alloying upon the surface of one such metal, a second metal or alloy of low melting temperature, a deoxidizing metal, and a metal of high melting temperature.

10. The process of producing compound metal bodies of unlike metals, which comprises alloying between approximate surfaces of such unlike metals, a metal or alloy melting below7 900o F., and a deoxidizing metal which is plastic above 900 F.

11. The process of producing compound bodies of unlike metals, which comprises contacting the surface of a tin-coated steel base with a semi-molten mass of a deoXidiZed metal.

12. The process ofproducing 'compound bodies of unlike metals, which comprises contacting vthe surface of a tin-coated steel base with a semi-molten deoXidized metal and thereafter causing a body of molten copper to combine therewith and solidify thereon.

13. The process of producing compound bodies of`unlike metals, which comprises coating a steel base with a plurality of coat- Yings including one of ay semi-molten mass of deoxidized metal and thereafter causing another metal to combine therewith.

14. The process of producing compound metal bodies of unlike nature, which comprises film-coating the surface of an iron base with a metal or alloy having a meltingpoint below 900o F., then contacting such film-coated iron base With adeoxidized metal having a melting-point above 900o F., said deoXidiZed metal applied in a semi-molten condition, and thereafter causing a substantial coating of a` cupriferous metal to combine therewith. l

15. The process of producing compound metal bodies of unlike nature, which comprises film-coating the surface of an iron base with a metal or alloy melting below 900 F., then contacting such film-coated iron base with a deoxidized metal having a melting-point above 900o F., said deoxidized metal applied in a semi-molten condition and thereafter causing a substantial coating of copper to combine therewith.

16. The process of producing compound metal bodies of unlike nature, which comprises Afilm-coating the surface o f an iron base with a metal or alloy melting below 900 F., then contacting such film-coated iron base with a deoXidiZed metal having a melting temperature above 900o F., said deoxidized metal applied in a semi-molten condition and thereafter causing a metal of unlike nature to combine with said base.

17. The process of producing compound metal bodies of unlike metals, which comprises coating the surface of one such metal with metal or alloy having a. melting-point below 900o F., then contacting the coated surface with: an alloy containing such other` metal and a deoxidizing metal -at a semimolten temperature, and causing the deoxidized metal to remove impurities, oxids, and occluded gases along the surface of union of the metals caused to combine therewith.

18. The process of producing compound metal bodies of unlike nature, which comprises coating the surface of one such metal with a. metal of low melting temperature, next 'with a metal or alloy at a temperature intermediate between its solid and molten liquid state, and then with a metal in its molten liquid state.

19. The process of producing compound metal bodies of unlike metals, which comprises coating the surface of one such metal with a metal or alloy of low melting temperature, then further coating the coated surface thereof with a deoxidized metal or alloy at semi-molten temperature, and limiting the thickness of the second coating secured by the period of time that the article to be coated is immersed in the bath of semimolten metal.

20. The process of producing compound met-al bodies of unlike metals, which comprises contacting the surface of one such metal with a metal or alloy of low melting temperature. then contacting and coating it with afdeoxidized metal at semi-molten temperature, and limiting to infinitesimal thickness the uniting layer thereby formed by limiting to a brief period the time of contact between the metal coated with metal of low melting temperature and the deoxidized metal used.

21. The process of producing compound metal bodies from liquid and solid metals, which comprises deoxidizing the contacting surfaces of the liquid and solid metals to be united, by a film-coating of a deoxidizing metal or alloy.

22. The process of producing compound metal bodies from liquid and solidmetals, which comprises contacting and deoxidizing the surfaces of heated liquid and solid mechas metals to be united, by an intermediate filmcmitng of a deoxidizing metal or alloy.

23. T he process of producing compound nie-tal bodies, \\hich`compi'ises deoxidizing and coating a surface of a. metal with a deoxidizing metal or alloy, said coating secui'ed to said first metal by the agency of a prior coating of a third metal, and then contacting thc deoxidized inetal or alloy coating so secured with ar substantial body of another metal to be united thereto.

24. The process of producing compound metal bodies, which comprises coating a surface of inetal with a inetal of 10W-melting temperature, deoxdizing and further coating said coated surface with a deoxidizing metal or alloy, contacting said second coated surface with a metal or alloy to be united thereto, and deoxidizing the surface of contact of the contacting metal or alloy by the deoxidizing meta-1 coating.

In testimony whereof I affix my signature in presence of two Witnesses.

oirTo H. DE LAPoTTERiE. 

